Anti-rolling and anti-pitching system for a motor vehicle, and device for making the same

ABSTRACT

An antiroll and anti-pitch device for a vehicle having four wheels provided in a two-by-two arrangement, including a central resilient element, two central actuating elements, four wheel actuating elements, and four wheel transforming elements. Each of the wheel actuating elements is associated with one of the four wheels and capable of providing a transmitting force caused by a vertical force to which the associated wheel is subjected. The central resilient element is capable of opposing a force provided by a first of the central actuating element and a force provided by a second of the central actuating elements.

FIELD OF THE INVENTION

This invention relates to an anti-roll and anti-pitch system for avehicle, and to the devices for its implementation, specifically asystem to be applied to vehicles provided with four wheels. The systemeither cooperates with the vehicle's suspension system or substitutesfor the vehicle's suspension system in order to allow the four wheels tokeep contact with the ground and to keep an even distribution of loadeven if the vehicle is subject to uneven terrain. Where the wheels areprovided in a two-by-two manner, the wheels that diagonally oppose eachother are related in such a way that the loads created by the verticalmovements of one of the wheels is transmitted to the opposite wheel inorder to transmit such a force that creates a similar movement in thevertical direction of the opposite wheel. The system cooperates with thesuspension of the vehicle, or is substituted for the suspension of thevehicle in order to allow all of the vehicle's wheels to keep contactwith the ground even if the terrain is irregular and prevents unwantedeffects that are caused by the uneven terrain.

A vehicle suspension is built mainly with coil springs and resilientelements that bear the vehicle body and transmit its weight and theinertial forces to the wheels. This provides a means to absorb thevibrations caused by the travel of the vehicle over the roadirregularities. Such springs and elastic elements are accompanied withshock absorbers in order to minimize the sprung movements and to avoidprolonged oscillations.

In addition to absorbing vibrations or shocks from the road surface, avehicle suspension must provide a safe ride, keeping an optimal positionin the straight trajectory, and vehicle safety during cornering.

Vehicle stability is strongly related with the oscillations of thevehicle body along its course when the vehicle experiences heading,pitch, and roll movements in addition to rebounds. Such oscillationshave to be absorbed to increase the stability and comfort of vehicleride.

STATE OF THE ART

Stabilizing bars are well-known means used to control the roll naturallygenerated when the vehicle is in operation.

A conventional anti-roll system uses a stabilizing bar that has a smallresilient component to provide adequate comfort during the ride. Thissystem, however, cannot accomplish its purpose satisfactorily when thevehicle turns, due to the centrifugal force generated when cornering.

On the contrary, if the anti-roll bar is very stiff, it will interferewith the suspension system and will impair the comfort of the vehicleride.

In U.S. Pat. No. 2,840,387, the forces created in a vehicle wheel as itturns are transmitted by two tie-rods to the diagonally opposed wheel,which reproduces the force in the same direction. In U.S. Pat. No.3,147,990, the wheels on one side of the vehicle are connected to eachother and also to those on the other on the other side by means oftorque arms. In U.S. Pat. No. 3,992,026, right and left torsion barsgenerally extend in the longitudinal direction and interconnect theright and left sides of a front anti-roll bar with right and left rearsuspension arms, respectively. In U.S. Pat. No. 5,505,479, two frontsuspension lower arms are aligned transversally between opposite frontand rear wheels, and connected by a resilient element locatedlongitudinally, for the purpose of transforming the vertical movementsof the wheels into a rotary motion as seen from the front of thevehicle. U.S. Pat. No. 5,882,017, a perpendicular connecting rod iscoupled to the vehicle and a pair of articulating elements link suchconnecting rod to the front wheels, including a pair of travel limitsselectively actuated that communicate with the central part of suchconnecting rod.

In ES 2110 509, the forces created in one wheel are transmittedhydraulically to the diagonally opposed wheel, using double-effecthydraulic cylinders. In WO 95/23076, similar to the above, the forcescreated in one wheel are transmitted to the diagonally opposed wheel bymeans of double-effect cylinders and, in one case, the single-effectcylinders connect the wheels on one side to each other and to a centraldevice. In FR 1.535.641. U.S. Pat. No. 3,752,497 and U.S. Pat. No.5,447,332, double acting hydraulic rams are used on each wheel providedtwo-by-two. The last two patents having a central device that relatesthe four wheels and includes a double or triple hydraulic cylinder wheresome linked pistons move in the same direction.

SUMMARY OF THE INVENTION

All known anti-roll systems interfere to some extent with the existingsuspension system, as they have to show a critical resiliency to suitstability and adaptability to uneven terrains.

Therefore, it is desired to have an anti-roll system, and also ananti-pitch system that would not interfere in geometric terms with theexisting suspension system, and that can cooperate with the suspensionsystem or substitute for the suspension system, being able to show anarbitrary rigidity without compromising the vehicle stability.

With such premises, an anti-roll and anti-heading system for a vehiclehas been developed that, along with its implementation devices, providesthe object of present invention. In this system the wheels are relatedthrough interaction means that receive the effect from one or morewheels before transmitting the effect to the other wheels in order tomaintain a uniform load distribution of the weight and reduce thevehicle heading and rolling.

The invention assumes that the forces created by the vertical movementsfrom one wheel is transmitted to the diagonally opposite wheel eitherthrough mechanical means able to resiliently resist forces of traction,compression, torsion and flexion, through hydraulic means, throughpneumatic means or through electrical or electronic means used tocommand servo actuators on each wheel. These means can be providedeither separately or any combination.

According to the above-mentioned possibilities of implementing thesystem, the invention includes several cases of proper devices toimplement the current system.

As in this invention, an anti-roll and anti-pitch device for a vehiclecomprises a receiving element connected with a first wheel of thevehicle, which transmits the wheel vertical movements to a directtransforming element that converts the vertical movements intohorizontal movements. An inverse transforming element converts thesehorizontal movements into vertical movements that are transmitted to asecond wheel diagonally opposed to the first wheel, causing a verticalmovement analogous to the movement of the first wheel.

In all these cases, the direct transforming element is related with theinverse transforming element by means of a transmission element that canbe mechanical, hydraulic, pneumatic or electric.

One characteristic of this invention is the case where receiving andactuating elements are made of a rod connected on one end to one wheelthrough a universal joint, while the other end is articulated to adirect transforming element in the receiving end case, and to an inversetransforming element in the case of an actuating element. In this case,the direct transforming element is a first kind angled connecting rod,and the inverse transforming element is a second or third kind angledconnecting rod, which pivot points are supported by the vehicle bodythrough bearings.

According to this invention, the transmission means between pairs ofdirect and inverse transforming elements are made up by a rigid bar,connected at its ends with each transforming element. It has beenanticipated too that the transmission means can be made of two flexiblestays, in which case the two transforming elements are made of threearms connecting rods shaped as “T”, with the pivot point near theintersection, the stays connected to the two ends of the shorter arms,and the third arm of both transforming elements working in the verticaldirection.

It is also a characteristic of this invention that the resilientelements connected to the transmission elements are connected to thevehicle body through an articulated balance beam, in such a way that theits ends are connected to the resilient elements and the center isjoined to the vehicle body.

Another characteristic of this invention is that the receiving andactuating elements can be the rods of pistons of single effect hydraulicrams, which are in turn the direct and inverse transforming elements,related through hydraulic conduits.

In one case, the hydraulic circuit is constituted by the two singleeffect hydraulic cylinders, which are the direct, and inversetransforming elements, and a hydraulic conduit that includes an insertedactuating device to keep the pressure in the circuit.

It is also a characteristic of this invention that when each receivingand actuating device is made up of single effect rams, the direct andinverse transforming elements are organized through interaction meansmade up of a central device built as a hydraulic ram containing twoopposed concentric pistons with same areas each, and a spring orpressurized fluid acting in between of them, having each cylinder end acoaxial cylindrical compartment in correspondence with the activesections of such pistons, having each compartment a connection with therespective receiving or actuating element.

There is another preferred implementation where the interaction meansthat are related with each pair of wheels is built as a centralhydraulic device made of three concentric coupled cylinders, closed atthe ends of the set, where the central cylinder is of a larger diameter,and the two cylinders at its sides are both of equal diameter, havinginside the cylinders two double-pistons, with no external rod, and onelarger piston found inside the central cylinder, and a smaller piston inone of the smaller cylinders, in such a way as to determine fivecavities: one central cavity, and two pairs of cavities at each side ofthe device separated by the smaller diameter pistons, being the doublecavities at each end of the device connected respectively to thehydraulic conduits corresponding to hydraulic single effect rams at eachdiagonally opposed wheeling set, while the central cavity is connectedto an actuating device built with resilient means and/or a fluidsusceptible of being connected to an expansion chamber that opposes tothe two double pistons getting closer to each other.

Another characteristic of the invention is that the central devicecentral cylinder has an area approximately double to the areas of eachside cylinder.

It is evident that with the appropriate modifications, such hydraulicelements can be adapted to become of pneumatic type.

The invention anticipates that the resilient means in the central cavityare actually provided by two elastic elements, each actuatingindependently on each of the larger pistons that close such centralcavity, so the central hydraulic device is divided in two halves relatedthrough an additional conduit provided of flow regulation means.

Each double piston in the central hydraulic device can be built from twoor more conventional pistons, linked with each other although actuatingeach one on independent hydraulic single effect rams, in such a way thatthe two or more new cavities of the new cylinders come to substitute thetwo pairs of cavities formerly separated by each piston of smallerdiameter following the diagonal scheme, and linking the two groups ofpistons through a resilient element acting as the former central cavity.

The invention contemplates the following facts:

-   -   a) Hydraulic fluid regulation or damping devices are inserted in        the hydraulic conduits from the central device to each hydraulic        ram linked to the wheels, or in between the cylinders associated        to conjugated wheels.    -   b) The central cavity, the two pairs of side cavities, the        conduits that connect these with the hydraulic rams at each        wheel, or the hydraulic cylinders can be connected to one or        more expansion pneumatic chambers through electro valves.    -   c) The four conduits that connect the double side cavities from        the central hydraulic device to each hydraulic ram at the wheels        is susceptible of being communicated through devices that allow        a limited volume flow depending on the pressure differential        between the conduits, being these devices preferably applied        between conduits to wheels at the same side of the vehicle.

It is also possible to provide the means of introducing pressurizedhydraulic or gaseous fluid in the central cavity, or drain it, with thepurpose of varying the average distance between the wheels and thevehicle body. For this purpose it can also be used a mechanical deviceto provide a thrust between the two larger diameter pistons found in thecentral cavity of the central hydraulic device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic representation of the anti-roll and anti-pitchsuspension system for a vehicle.

FIG. 2 is a diagrammatic representation of the device that relates twodiagonally opposed wheels through a single push-pull strut.

FIG. 3 is a diagrammatic representation of the device that relates twodiagonally opposed wheels through a single torsion bar.

FIG. 4 is a diagrammatic representation of the device that relates twodiagonally opposed wheels through an articulated torsion bar.

FIG. 5 is a diagrammatic representation of the device that relates twodiagonally opposed wheels through a pair of pull-only flexible stays.

FIG. 6 is a diagrammatic representation of the device that relates twodiagonally opposed wheels through single effect hydraulic rams.

FIG. 7 is a diagrammatic representation of the device that relates twodiagonally opposed wheels through servo actuators and anelectrical/electronic circuit.

FIG. 8 is a diagrammatic perspective representation of the transverseconfiguration for the wheels torsion bars related diagonally in pairsthrough two transmission bars crossing over at some point.

FIG. 9 is a diagrammatic perspective representation of rear side ofconfiguration showed in FIG. 8 where such transmission bars areconnected to the vehicle body through independent resilient elements.

FIG. 10 is a diagrammatic perspective zoomed representation of theresilient elements in FIG. 9.

FIG. 11 is a diagrammatic representation of a configuration similar toFIG. 9 where the independent resilient elements are placed at a midpoint of the transmission bars.

FIG. 12 is a diagrammatic zoomed perspective representation of theconfiguration of FIG. 11.

FIG. 13 is a diagrammatic representation of a detail like FIG. 12 wherethe two resilient elements are not independent and are related through abalance beam.

FIG. 14 is a diagrammatic representation of a detail like FIG. 10 wherethe two resilient elements are not independent and are related through abalance beam.

FIG. 15 is a diagrammatic perspective representation of transverseconfiguration based on torsion bars where the transmission bars areequally crossed and connected through a common resilient element in thiscase under compression.

FIG. 16 is a diagrammatic perspective representation of a longitudinalconfiguration based on torsion bars where the transmission bars arelocated transversely.

FIG. 17 is a diagrammatic perspective representation of a configurationfor a four-wheel vehicle based on torsion bars related through crossedtransmission connected to a common resilient element.

FIGS. 18, 19 and 20 are is a diagrammatic perspective and zoomedrepresentations of details of FIG. 17.

FIG. 21 is a diagrammatic representation of a hydraulic device withsimple effect rams applied to the four vehicle wheels.

FIG. 22 is a diagrammatic representation of a hydraulic device withsimple effect rams applied to the four vehicle wheels.

FIG. 23 represents a section of the implementation of the centralhydraulic device found in previous FIG.

FIG. 24 represents a perspective section of the implementation of thecentral hydraulic device found in FIG.

FIG. 25 is a diagrammatic representation of an alternativeimplementation of the central hydraulic that has is functionallyequivalent to the device represented in FIGS. 22 and 23.

FIG. 26 is a diagrammatic representation of multiple expansion chambersthat allows the adjustment of suspension stiffness.

FIG. 27 is a diagrammatic representation of limited volume transfer tobe inserted between two hydraulic circuits.

DETAILED DESCRIPTION

The proposed anti-roll and anti-pitch suspension system relates, asrepresented in FIG. 1, the pairs of diagonally opposed vehicle wheels,in such a way that the forces created by the vertical movements of oneof them are transmitted to the conjugated wheel in order to communicatea force that determines analogous movements in the same verticaldirection.

FIG. 1 shows the front-left wheel A, front-right wheel B, rear-leftwheel C and rear-right wheel D. The proposed system relates wheels Awith D, and wheels B with C.

The axis of each wheel A, B, C and D is linked with a rigid element 1,which in turn is connected on wheels A and B to first kind connectingrods pivoting on 3, and on the other wheels to second or thirdconnecting rod 4 pivoting on 5, being each connecting rod 2 related withconnecting rod 4 diagonally opposite through a transmission element 6.

FIG. 2 shows how a vertical force FB created by the terrainirregularities on the element 1 of wheel B is transformed through thecorresponding connecting rod 2 into a non vertical force F that goes tothe corresponding connecting rod 4 and gets transformed into a verticalforce FC analogous to FB in direction and intensity.

The transmission of forces determined by the vertical movements in anyof the two wheels of a diagonally opposed set is carried throughmechanical means able to resiliently resist traction, compression,torsion and flexion forces, hydraulic and/or pneumatic means, andelectric and/or electronic means that actuate through actuators on eachwheel.

In general, this system can be implemented through a device as describedbelow following again FIG. 2.

The device has a rigid element 1 that related with a first vehicle wheelB transmits its vertical movements FB to a direct transforming elementsuch as connecting rod 2 that transforms them into horizontal ornon-vertical movements, which in turn are transmitted through theelements 6 into an inverse transforming element such as connecting rod 4that transforms these horizontal movements into vertical movements ofthe rigid actuating element 1 of a diagonally opposite second wheel C,subject then to a vertical movement analogous to the first wheel.

We have named receiving element or actuating element to the same rigidelement 1, using the first meaning when this is the element thatreceives the terrain irregularity, and the second meaning when itactually transmits the movement to the wheel, so on both wheelsreceiving and actuating elements are the same. Analogously we can applythe same convention to the inverse and direct transforming elements.

In one of the implementations of this device, the rigid elements 1acting as receiving or actuating element, are made up by an articulatedconnecting rod, linked through a joint 7 to one wheel at one end, andthrong a second joint 7 to a direct transforming element in the otherend, being this transforming element made of a first kind angledconnecting rod 2 when the rigid element 1 works as a receiver, and aninverse transforming element made of a second or third kind angledconnecting rod 4 when the rigid element 1 works as an actuator.

The transmission means 6 are made up by: a rigid bar linked at each endto the transforming elements 2 an 4 as seen in FIGS. 1 and 2; aone-piece torsion bar 8 linked to the vehicle body at point 9 such as inFIG. 3; by a torsion bar articulated through universal joints 10 as inFIG. 4; and by two flexible pull-rods 11 as in FIG. 5, where the twotransforming elements are made of “T” shaped connecting rods 12 of threearms pivoting on 3 near the intersection, being the ends of the alignedarms connected to through joints 7 the ends of the crossing pull-rods11, in such a way that the third arm actuates along the same verticaldirection at each rigid element 1 working as receiving or actuatingelements.

Another implementation of the invented device, as seen in FIG. 6, therigid elements are the rods 13 connected to the pistons 14 of singleeffect hydraulic rams 15 mounted through a joint 15A to the vehiclebody, being such pistons the direct and inverse transforming elements asshown in FIG. 6, where the hydraulic rams 15 are related throughconduits 16 that have an actuating device 17 that using hydraulic rams18, elastic elements 19 and/or pneumatic means 20 keep the pressure inthe circuit.

FIG. 7 represents the case where each wheel has a conjugated pair of aservo actuator 21 related to a control unit 22.

As seen in FIG. 8, direct and inverse transforming elements are made oftorsion bars 23 with an arm 24 at each end; one connected to one wheelsupport 25, and the other to a transmission element 26. Suchtransmission elements 26 cross over in order to diagonally relate eachconjugated pair of wheels.

As seen in FIG. 9 and detail FIG. 10, each transmission element 26A, 26Bis connoted to the vehicle body through an elastic element such as acoil spring 27 placed between two brackets, one 28 fixed to the vehicle,and the other 29 fixed to the end of the transmission element.

The placement of coil springs 27 can be implemented as indicated inFIGS. 11 and 12, where the transmission elements 33 are made of twosegments 26A and 26B joined at a plate 30 attached to a coil spring 27.Such spring is mounted between two brackets 28 and 29, the former fixedto a crossbeam 31 mounted on the vehicle body, having two rods 32 as aguide for the coil springs 27 and pushing ends 33 applied to the plates30 that pass loosely through.

FIG. 13 shows a configuration where the two coil springs 27 linked tothe transforming elements 26A, 26B are related with the vehicle bodythrough the balance beam 34, linked to the vehicle body through an axisgoing through the pivot point 35, and to the rods 32 at its ends, havinglike the previous case pushing ends 33.

FIG. 14 shows a different configuration for balance beam 34 that has thebrackets 28 and 29 at the ends of its arms with coil springs actingunder compression like in FIG. 9.

FIG. 15, as in previous figures, shows the layout of the transformingelements 23 with a single compressing spring coil 27 that links the twocrossing transmission elements 26 arranged in two parallel planes.

FIG. 16 shows a layout where the direct and inverse transforming axisare arranged longitudinally in respect to the vehicle, and thetransmission elements 26 are crossed in the transverse direction, havingone single coil spring 27.

FIG. 17 is a representation of a mechanical layout similar to FIG. 15where the transmission elements 26A′ and 26B′ are arranged on the sameplane, side by side through the single coil spring 27 mounted betweenthe brackets 37, each of them joined to fixtures 38 and 39 each linkedto one transmission element 26A′ and 26B′ as shown in the detail view19.

As it can be seen in FIGS. 18 and 20, the transmission elements 26A′ and26B′ are crossed over by means of the connecting arms 24A–24D, so thearm 24B is related to arm 24C, and arm 24A to arm 24D.

In this invention, the elastic elements connected to the vehicle bodycan be mounted on one or two mechanic, electro mechanic or hydraulicactuating elements such that their movement in respect to the vehiclebody varies its height in respect to the ground; the balance beam axiscan be mounted on one or two mechanic, electro mechanic or hydraulicactuating elements such that their movement in respect to the vehiclebody varies its height in respect to the ground; and the centralresilient element can have a mechanic, electro mechanic or hydraulicactuating element able to move one of the resilient element fixtures, insuch a way that varies its effective length, and by so varies the heightof the vehicle in respect to the ground.

FIG. 21 shows a variation where each receiving and actuating element ofthe two pairs of vehicle wheels is made up by the rods 40 of pistons 41of single effect hydraulic rams 42, the direct and inverse transformingelements are arranged in a unique central hydraulic cylinder 43containing two free moving and opposed pistons 44. Active areas 45 areequal and concentric, and are subject to an internal actuator made of acoil spring 46 and/or pressurized fluid 47 On the outer side of eachpiston, a cylindrical compartment 49 and a coaxial compartment 50corresponds to the active sections of each piston. Each compartment 50and 49 communicates with a connection 51 that extends towards thecorresponding receiving and actuating element 40 for each of thediagonally opposed wheels.

In the above implementation, the active central section of free-movingpistons 44 can be eliminated, acting as active area the inner face wherethe coil spring is applied.

The actuating devices can be made up with a pair of single effecthydraulic rams as in FIG. 6, with a common acting force. Such twocylinders can be concentric and of equal active area, be made up fromthree cylinders where one is equivalent to the other two, or four equalrams arranged at the ends of a cross.

FIGS. 22 and 23 represent a variation where the central hydrauliccylinder 43′ is made up joining three hollow concentric cylinders, witha central cylinder 52 has a larger diameter, and the side cylinders 53are the two equal and of smaller diameter, closed at their free ends 54.Inside such hollow body there are two free moving double pistons 55 madeup one larger diameter piston 55A placed inside the larger centralcylinder 52, and a smaller piston 55B placed inside the correspondingend cylinder 53, thus determining one larger central cavity 56associated to the central cylinder, 52, two smaller intermediatecavities 57 and 58, and two smaller ending cavities 59 and 60 associatedto the side cylinders 53, all cavities connected in such a way that thesmaller intermediate cavities 57 and 58 are respectively communicatedwith the simple effect hydraulic ram 42 for wheels B and A, while thesmaller end cavities 59 and 60 are respectively communicated with thesimple effect hydraulic ram 42 for wheels C and D. The central cavity 56has an actuating device made of resilient means such as pressurizedfluid 62, coil spring 46 or rubber-like body, the two last cases notrepresented in FIG. 22. One preferable implementation of such centralhydraulic device 43′ is shown in FIGS. 23 and 24.

Preferably, the area of the central cylinder 52 is approximately doublethe area of each side cylinders 53.

The resilient means used in the actuator in the central cavity can bemade of a double resilient element that independently pushes pistons 55Athat close such larger central cavity 56. Another possibility is todivide the central hydraulic device 43′ in two halves that communicatethrough an additional conduit that has means to regulate the flow of thefluid.

FIG. 25 shows an arrangement of the central hydraulic cylinder 43″,where each double piston is made of two or more related pistons 63 insingle effect hydraulic independent rams 64. The two or more cavities ofthese new cylinders can substitute the two intermediate smaller cavities57 and 58 and end cavities 59 and 60 that are separated by the smallerdiameter pistons 55B shown in FIG. 24. The hydraulic conduits 61 areconnected in a diagonal arrangement, and are communicated by the rods 65of the two groups of pistons 63 through a single resilient element 66acting as the actuating device used in the larger central cavity 66.

FIG. 22 shows how two-way regulation or damping devices 67 are insertedin the pipes and connect the central hydraulic device with all simpleeffect hydraulic cylinders 42 associated with the wheels. Additionally,the larger central cavity 56, the smaller intermediate cavities 57 and58, the end cavities 59 and 60, the hydraulic conduits 61 that connectthe cavities with the hydraulic rams 42 associated to each wheel and thevery hydraulic rams 42 are connected to the damping devices 67, whichcan be one or several pneumatic expansion chambers 68 that can bedisconnected through electric valves 69, such as these represented inFIG. 26.

On the other side, the four main hydraulic conduits 61 that connect thesmaller cavities 57, 58, 59 and 60 of the central hydraulic device 43′with the simple effect hydraulic rams 42 associated to the wheels aresusceptible to be connected among them through devices that allow theflowing of a limited quantity of fluid depending on the pressuredifferential between the hydraulic conduits. This communication ispreferably applied between hydraulic conduits from wheels of the sameside of the vehicle. FIG. 27 shows this device made up with afree-moving piston 70 between two coil springs 72 inside cylinder 71.

It has also been anticipated having means to provide pressurizedhydraulic or gaseous fluid or drain it from the larger central cavity 56with the purpose of varying the average distance between the vehiclebody and the wheels. For example, FIG. 21 shows an entry M of fluidpressurized by a pump P, and FIGS. 23 and 24 show an entry M′. The sameresult is obtained including a mechanical device that pushes the twolarger diameter pistons 55A placed in the central cavity 56 in thecentral hydraulic device 43.

Therefore cavity 56 can include one or various resilient elements thathave one or various mechanical, hydraulically or electromechanicalactuators that can vary the average distance between the vehicle bodyand the ground.

Additionally it has been anticipated that each hydraulic conduit 61 isderived into one or more devices with a variable volume cavity such asthat the circuit pressure increases, it compresses a resilient orpneumatic element that facilitates the entry of hydraulic liquid in thecavity. Analogously, each hydraulic conduit can have one or moreregulating devices or valves, passive or active for the hydraulic fluid.

This invention anticipates that one or more wheels are substituted bysets of wheels, each wheel has one single effect hydraulic ram, and allrams communicated among them and with the hydraulic conduit of the wheelset corresponding to the central hydraulic device. Such substitution canbe applied to a caterpillar device.

The invention also contemplates the fact that a wheel set of can be usedin place of individual wheels. When more than one wheel is used, eachwheel has a corresponding single-effect hydraulic ram, and all thehydraulic rams for the wheel set are connected to each other and to thehydraulic central device through the conduit corresponding to the wheelset.

1. An anti-roll and anti-pitch device for a vehicle having four wheelsprovided in a two-by-two arrangement, comprising: at least one centralresilient element; two central actuating elements, wherein the centralresilient element is capable of opposing a force provided by a first ofthe central actuating elements and a force provided by a second of thecentral actuating elements; four wheel actuating elements, each of thewheel actuating elements associated with one of the four wheels andcapable of providing a transmitting force caused by a vertical force towhich the associated wheel is subjected; and four wheel transformingelements; wherein: each of the wheel transforming elements is capable oftransmitting the transmitting force from an associated one of the wheelactuating elements to one of the two central actuating elements; the oneof the central actuating elements that receives the transmitting forceis capable of transmitting the transmitting force to an other of thewheel transforming elements; the other of the wheel transformingelements is capable of transmitting the transmitting force to an otherof the wheel actuating elements associated with a wheel diagonallyopposed to the wheel that is subjected to the vertical force; and theother wheel actuating element is capable of providing a correspondingvertical force, which is in a same direction as the vertical force towhich the associated wheel is subjected, to the diagonally opposed wheelbased on the transmitting force.
 2. The device according to claim 1,wherein the at least one central resilient element includes tworesilient elements connected to a vehicle body through a balance beamhaving a central axis and two arms, wherein the two arms of the balancebeam are connected to the two resilient elements, respectively, and thecentral axis is connected to the vehicle body.
 3. The device of claim 1,wherein: the wheel actuating elements include single effect fluid rams;each of the wheel transforming elements includes a fluid conduit; eachof the conduits is connected to one of the two central actuatingelements; and the central resilient element is a fluid cavity or aresilient component.
 4. The device of claim 3, wherein: each of thecentral actuating elements includes a pair of central devices, andwherein the pair of central devices of the first central actuatingelement are connected together, and the pair of central devices of thesecond central actuating element are connected together.
 5. The deviceof claim 4, further comprising a central cylinder of a first diameterand two concentric side cylinders of a second diameter, and two doublepistons, each double piston including a larger diameter piston providedin the central cylinder and a smaller diameter piston provided in one ofthe side cylinders; wherein: the pistons define a plurality of cavitieswithin the central cylinder and two concentric side cylinders, thecavities including a central cavity and two side cavities; wherein theconduits are hydraulic conduits and are connected to the cavities; andthe central resilient element opposes the movement of each of the largerdiameter pistons within the central cavity.
 6. The device of claim 5,wherein each of the central cavity, the two side cavities, and theconduits are connected to one or more pneumatic expansion chambersthrough electric valves.
 7. The device of claim 5, wherein one of saidconduits is connected to another of said conduits through devices thatlimit a volume flow between the conduit depending on a pressuredifferential between the conduits, wherein said one of said conduits isconnected to one of the two central actuating elements and the other ofsaid conduits is connected to the other of the two central actuatingelements.
 8. The device of claim 5, wherein the central resilientelement is a mechanical device that provides a thrust between the twolarger diameter pistons within the central cavity.
 9. The device ofclaim 5, wherein one of said conduits is shunt connected to another ofsaid conduits such that a pressure increment compresses a resilientelement that allows fluid to flow from said one of the conduits to theother conduit, wherein said one of said conduits is connected to one ofthe two central actuating elements and the other of said conduits isconnected to the other of the two central actuating elements.
 10. Thedevice of claim 5, further comprising passive or active regulatingvalves inserted in each of the conduits.
 11. The device of claim 4,wherein each of the pairs of central devices includes two pistons linkedto each other.
 12. The device of claim 3, further comprising a centralcylinder of a first diameter and two concentric side cylinders of asecond diameter, and two double pistons, each double piston including alarger diameter piston provided in the central cylinder and a smallerdiameter piston provided in one of the side cylinders; wherein: thepistons define a plurality of cavities within the central cylinder andtwo concentric side cylinders, the cavities including a central cavityand two side cavities; wherein the conduits are hydraulic conduits andare connected to the cavities; and the central resilient element opposesthe movement of the larger diameter pistons within the central cavity.13. The device of claim 12, further comprising means for introducingpressurized gaseous or hydraulic fluid to the central cylinder, and fordraining the central cylinder.
 14. The device of claim 3, furthercomprising a plurality of flow regulation and two-way damping means,wherein each of the flow regulation and two-way damping means areinserted in one of the conduits.